• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.792-797
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• 2009

The excess heat that is generated from PV modules can be removed and converted into useful thermal energy. A photovoltaic-thermal(PVT) module is a combination of photovoltaic module with a solar thermal collector, forming one device that receives solar radiation and produces electricity and heat simultaneously. In general, two types of PVT can be classified: glass-covered PVT module, which produces high-temperature heat but has a slightly lower electrical yield, and uncovered PVT module, which produces relatively lower temperature heat but has a somewhat higher electrical performance. In this paper, the experimental performance of two types of the PVT combined module(water type), glazed(glass-covered) and unglazed, was analyzed. The electrical and thermal performance of the PVT combined modules were measured in outdoor conditions, and the results were compared.

• Journal of IKEEE
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• v.22 no.3
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• pp.742-746
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• 2018

In this paper, we implemented a VLC(Visible Light Communication) system capable of transmitting/receiving data on a 30MHz clock based on On/Off keying modulation/demodulation. The data rate of the implemented system can be verified by functional verification of VLC channel composed of LED/photodiode driver and VLC transmitting/receiving signal of Tx/Rx platform. But, In the experimental results with the VLC transmitting/receiving for combined module, the maximum transmission rate was measured at 15 MHz. Therefore, we describe the problems that can occur when implement the VLC system using the LED module with output power of 15W or more and propose ways to improve it.

• Korean Journal of Optics and Photonics
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• v.32 no.1
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• pp.15-21
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• 2021

In this paper, an aircraft warning light's optical system was designed using an LED light-source module and a collimating Fresnel lens. As for the optical system, a collimator Fresnel lens was designed for each module to satisfy a vertical-elevation center luminous intensity of 20,000 cd and the divergence-angle luminous-intensity standard conditions of the Ministry of Land for Infrastructure and Transport for aircraft warning lights. In addition, the optical system was optimized by adjusting the position and tilt of the LED light-source module and Fresnel lens. By analyzing and comparing the light-distribution characteristics of the optical system, an aircraft-warning-light optical system with optimal performance was obtained.

• Convergence Security Journal
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• v.14 no.7
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• pp.29-36
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• 2014

In this study, we design and develop a VLC test-bed system which has been recently issued and focused as good convergence technology in the world. We classify the developed system into transmission part including analog LED driver module, digital signal modulation module, and receiver part with light sensing module and signal demodulation module. Then we introduce important characteristics and components. We analyze some factors for each module. To validate the communication of the designed VLC system, we develop a VLC sender-receiver simulator which can control the dimming factor and flicker-free effect. From the developed system, we observed about 12Mbps of data transmission rate with 0.5m~1m of distance, without packet loss. We verified the real-time communication with multimedia streaming which can be considered as very high date rate. The developed system and technology will be useful for some converged data services like indoor positing, home appliances, and indoor parking system.

• Journal of Korean Association for Spatial Structures
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• v.10 no.1
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• pp.67-74
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• 2010

This paper focuses on steel arrays regarding the application of PV system for solar power system, a renewable energy in steel structure stadium that will be built in Korea, by foreign case study. 20 cases of Steel Structure Stadiums applying PV system after 1990 were selected as the main subjects. The 20 cases of Steel Structure Stadiums were categorized by rail systems that were installed to fix PV module. As the result, linear clamping and roof-integrated type among cross rails were 28% of the whole, followed by 17% of rail-fixed type and 11% of module group-fixed type among vertical-fixed types. In addition, linear clamping and roof-integrated type among cross rails were applied in the inside of the stadium while the outside and other parts of stadiums used angle bracket to fix PV module.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.668-670
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• 2017

Visible Light Communication, which is promising as a next generation near field wireless communications, has been increased study and application case due to the development of LED technology. However, there are few application cases to IoT service due to the necessity of separate equipment for communication and limitation of light transmission to obstacles. In this paper, it propose a portable VLC transceiver module that can be connected to USB OTG and dedicated application for control to realization position possible necessary technique. The string input from the dedicated application is sent to the VLC module via USB OTG to transmit and receive data between the modules. As string transmission experiment result, it is confirmed that ASCII code transmission between VLC transceiver modules is possible through control of the implemented dedicated application.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.261-262
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• 2011

본 논문에서는 태양광 발전 시스템의 일사량 불균형 환경에서 출력 전력을 최대화 하기위한 DC-DC 모듈 집적형 전력변환장치에 요구되는 동작에 대하여 알아보고 이를 제어하기 위한 알고리즘을 제안한다. 토폴로지는 구조가 간단하고 제어가 용이한 Cascaded Buck-Boost 컨버터를 대상으로 한다. 제안한 알고리즘을 PSIM을 이용한 시뮬레이션을 통해 검증한다.

• Proceedings of the KIPE Conference
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• 2011.11a
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• pp.287-288
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• 2011

주택 혹 산업용, 공공건물용으로 상용화 되어 있는 스트링 어레이 중앙 인버터 방식은 고압의 DC 배선으로 인한 안전문제, 고가의 고압 DC 차단기의 설치 및 과전압보호기 등으로 가격이 상승하게 되고 설치 시에도 패널간 균일 성능을 보장해야하고 스트링 상에 놓여 있는 패널 일부가 불량이거나 그림자가 져서 발전이 미비할 경우 전체 시스템 발전이 정지하거나 발전량이 미비해지는 문제가 생기므로 항상 최적의 상태로 운전할 수 없다. 그래서 이러한 태양광 발전 방식의 문제점을 해결하기 위해 각 모듈마다 마이크로 인버터를 장착하여 각각 패널마다 분산적인 MPPT(Maximum Power Point Tracking) 를 수행할 수 있고 DC 배선이 없기 때문에 시스템 설치비용을 획기적으로 절감할 수 있으며 안정성 문제도 중앙 인버터 방식보다 획기적으로 향상된다. 패널 또는 인버터 고장 시 전체 시스템의 차단 없이 교체가 가능 하여 시스템의 설비 이용률을 최대로 할 수 있다. 이러한 패널에 쓰이는 마이크로 인버터를 PSIM으로 구현하여 DLL로 통해 디지털 제어로 구현을 하고 시뮬레이션으로 통해 시스템의 효능을 알아보았다.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.120.1-120.1
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• 2011

Increase the efficiency of PV modules for high-efficiency solar cells, light transmittance improvements, increasing the module, and much more research and development. Dual we light transmittance for photovoltaic module materials in low iron tempered glass in SiO2 using liquid AR implementation, light transmittance to solar modules to increase the efficiency of research.

• Proceedings of the KIEE Conference
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• 2008.05a
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• pp.149-150
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• 2008

본 논문은 가로등 LED조명 설계를 위해 LED(Light Emiting Diode)소자 특성 분석 및 시뮬레이션을 통해 광특성을 개선하고자 하였다. $30^{\circ}{\sim}50^{\circ}$ 사이의 2차 렌즈 설계를 통해 조도 분포 특성 및 광분포 특성을 확인하였으며 LED 모듈의 간격 배열을 통해 램프를 설계 하고자 하였다. 그 결과 2차렌즈 35도 각도와 LED 소자간의 간격을 3Cm로 설정할 경우 최적의 광 특성을 확인할 수 있었다.